Sample_growth_protocol_ch1: Media. The composition of the synthetic medium [1] for shake-flask and chemostat cultivation was as follows: 5 g.l-1 (NH4)2SO4, 3 g.l-1 KH2PO4, 0.5 g.l-1 MgSO4 and trace elements. The media was sterilized by autoclaving at 120 oC. Glucose (25 g.l-1 for chemostat cultivation), vitamins and the anaerobic growth factors Tween-80 and ergosterol, were supplemented after sterilization [1]. The glucose was autoclaved separately at 110 oC, and the vitamins were filter sterilized.

Sample_growth_protocol_ch1: Chemostat cultivation. Anaerobic glucose-limited steady-state chemostat cultures at a dilution rate of 0.10 h-1 of S. cerevisiae CEN.PK113-7D were performed as previously described [2]. Iso-α-acid enriched hop extracts were filter sterilized and added at a concentration of 0.2 g.l-1. Medium reservoirs containing iso-α-acid enriched hop extracts were stored at 4ºC and protected from light.